Yes, I try to power on/off in the correct sequence but forget once in a while, and it does it every time.
Pass DIY Addict
Joined 2000
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Powering off my Pearl2 with the amp running produces a copious "farting" type of oscillation through the speakers. It was a little alarming the first time, so I just make sure to power up the Pearl before I power up the amp. Another solution that works - I use a separate preamp - is to have the pre on a different input while I power up/down the Pearl2.
Have you done the mod of adding a cap in series with R14? This will lessen the turn on thump that is probably tripping the protection circuit. At least it did with mine.
Wayne recommends between 47 and 470uF. I used a 220uF electrolytic with a small film cap bypass.
We have a Denon receiver in the living room that we use for our home theater set up. When I first installed it I soon learned that if I accidentally turned it off and immediately tried to turn it back on it would go into protection mode. After this repeatedly happening I got frustrated and lifted the front half an inch and dropped it on the equipment rack. That fixed it!
It only happened one or two more times, each time repaired by giving it a thump. It hasn't happened since. Go figure. 😀 Based on my experience I would blame the Denon, not your Pearl.
It only happened one or two more times, each time repaired by giving it a thump. It hasn't happened since. Go figure. 😀 Based on my experience I would blame the Denon, not your Pearl.
Pass DIY Addict
Joined 2000
Paid Member
This behavior tells me you have a lose connection somewhere. Most likely, it is a ribbon cable that has either worked its way lose just a little, or the contacts have become tarnished. Either way, I would open it up and check each of the ribbon cables on the PCBs. Maybe separate each cable from its connector, spray some electronics cleaner into it and re-attach the cable. If this doesn't solve your problem, you need to look more deeply.
Hmmm. I never thought it might be something as simple as that. I was thinking of a defective relay of some sort.
if it happens again I'll open it up and take a peek!
if it happens again I'll open it up and take a peek!
Thanks - I'd have to see this drawn on the Pearl 2 schematic to understand what you're doing. Are you just replacing L2 with an adjustable regulator?
LM317/337 start off with better PSRR and lower noise than those designated U1, U2 in the schematic, and LM7924 can be difficult to source.
Initially, Q1 is "on", shorting R2. Capacitor C1 is charged by R1 - R3 over time, eventually turning Q1 "off".
If using an LM317/337 you should hang a 100uF aluminum electrolytic cap on the output "for stability reasons", and you can put 10uF across R2 which lowers the noise considerably.
Help please...My pearl has been sounding fantastic for 6 months or more so since the completed build but last week a horrid static noise (through the speakers) appeared. Bias I thought!! and sure enough one board was way up 1.2v the other board was also way off. I did get them within a 10-20mv 'steady state' at build.
So I reset bias 10-20mv steady state, plugged in all good but 4 days later the bias has drifted again.
I recall there was a fix for this floating bias issue but cant find the tread. Could one of good chaps point me in the right direction....
TIA
So I reset bias 10-20mv steady state, plugged in all good but 4 days later the bias has drifted again.
I recall there was a fix for this floating bias issue but cant find the tread. Could one of good chaps point me in the right direction....
TIA
On my vinyl rig, I never keep the selector switch to phono except when listening. Protocol for album change is, switch selector away from phono, change album, brush it off and clean stylus.. then switch selector back to phono. This prevents any turn on noise when unit is first switched on, and also prevents noise from stylus cleaning and any static pops from album change.
Yes, learned the hard way!
Russellc
Yup. Also prevents static pops from album changes and allows silent stylus cleaning. I always look at selector before doing anything phono.
Russellc
I clean with arm on rest, but not latched down. Any too hard and the arm goes up! I'm not sure what too hard sounds like...
Russellc
Russellc
